An organic light emitting diode (OLED) display device has advantages of low power consumption, high color gamut, high brightness, high resolution, wide viewing angle, high response speed, and the like. OLED display devices can be classified into two types: passive matrix OLEDs (PMOLEDs) and active matrix OLEDs (AMOLEDs) according to the driving method. The AMOLED has pixels arranged in an array, which belongs to an active display type, has high luminous efficiency, and is generally used as a high-definition large-sized display device.
AMOLED-based devices are current driven devices. When a current flows through the organic light emitting diode, the organic light emitting diode emits light, and the luminance of the light is determined by the current passing through the OLED itself. The conventional AMOLED pixel driving circuit is usually 2T1C, that is, a structure in which two thin film transistors and one capacitor are used to convert a voltage signal into a current signal. Such a pixel driving circuit is sensitive to the threshold voltage and channel mobility of the thin film transistor, the starting voltage, and quantum efficiency of the organic light emitting diode, and the transient process of the power supply. The threshold voltage based on the driving thin film transistor and the organic light emitting diode drifts with the time of operation, thereby causing the light emission of the organic light emitting diode to be unstable, causing differences in brightness in the display screen, and reducing the picture quality and the service life.
Therefore, in the process of implementing the present application, it has been found that the related art has at least the following problem: the current design for pixel driving cannot overcome the instability problem caused by threshold voltage drift of transistors and light emitting components, affecting display quality and service life.